Wasp impacts on native biodiversity

Learn more about wasps and their devastating impacts here:

Bandits of the Beech Forest

Although made 20 years ago, this documentary illustrates the extreme impacts introduced wasps have had (and continue to have) on our native biodiversity.

Recommended viewing and highly relevant even today.

Wiping out invasive wasps a 'critical issue' for New Zealand's environment

A pest control method inspired by Greek mythology is one of the latest weapons being developed in New Zealand's war on invasive wasps.
Professor Phil Lester of Victoria University spoke at Nelson Marlborough Institute of Technology on Tuesday night about a research project he is leading aimed at wiping out wasp populations.
Lester, an expert in insect ecology, said it was appropriate that he was giving the talk in Nelson, which he said was the "wasp capital of New Zealand".

Source: http://www.stuff.co.nz/environment/85957974/wiping-out-invasive-wasps-a-critical-issue-for-new-zealands-environment

Time to plan for the approaching wasp season

As summer approaches, common/german wasp queens will be out of hibernation and now building new nest sites. Wasp numbers will slowly build over the coming months. Now is a good time to make some wasp observations and plan for control measures. Ideally control needs to be planned and undertaken prior to wasps reaching plague level proportions.

Here are two simple steps to take:

1. Watch for wasp activity. Be aware of wasps and how common they are becoming around your property. Bees and bumble bees are being active right now so don't mistake them for wasps! Wasp activity will build over the coming months, so its good to get an idea of how common they are and how their numbers are building up. Taking note of where they are flying to and from. This might give clues as to where their nest is building. Finding a nest site really is a bonus- it makes control of localised wasp infestations relatively straight forward.

2. Watch for wasp feeding patterns. As wasp numbers build they will start looking for food sources. What are they feeding on? It's useful to know wasp feeding habits, because this is critical for control operations. Once wasp numbers build to being very common, place some test baits- fish cat food - a teaspoon in a milk bottle lid is fine. Put one or two out on a handy fence post near wasp activity. Wait an hour, go have a cup of tea, go back and see if wasps are actively feeding on this bait. Repeat this at weekly intervals- at some point wasps will switch their feeding preferences to this bait. As soon as wasp feeding preference for test baits are confirmed- this is the time to carry out control operations.

My measure for wasps becoming common is heaps of flying activity. A solitary wasp doesn't count for too much! But for example, when wasps start flying into your house and getting caught on windows trying to escape- that's a good measure of wasps becoming common. Wasps becoming a nuisance in the garden is also a sign their populations are starting to boom.

Found a wasp nest site? Wasps a nuisance? Contact me if you want any advice on control.

Tackling the Wasp Problem

They have a toxic sting that can kill a person and they're the most serious threat to our environment. In the native beech forests the drone of the wasps is so loud, you cannot hear the birds.
Victoria University Insect ecologist, Phil Lester is at the forefront of tackling the wasp problem. He says say that could involve making some tough decisions…

Listen to this radio discussion here:


Wasps Plague Riverbanks says HBRC

Wasps Plague Riverbanks

There is a population explosion of wasps along Hawke’s Bay riverbanks and Hawke’s Bay Regional Council is warning people to take care along river berm areas.

“If there’s a large amount of wasps around, our advice is to leave the area, and certainly avoid going into the undergrowth where you may disturb a wasp nest,” says Vince Byrne, HBRC’s rivers manager.
It is not known why wasps have increased to such large numbers in these areas but there have been reports of similar problems in other parts of the country. 


10 Facts about wasps

Here are 10 seriously worrying facts about wasps to consider.

  1. The German wasp (Vespula germanica) was first found near Hamilton in 1945; the common wasp (Vespula vulgaris) has been in New Zealand since 1978
  2. The beech forests at the top of the South Island have the highest densities of wasps in the world; but wasps also occur in many other habitats across New Zealand
  3. On average, there are 12 nests per hectare in beech forests, that’s about 10, 000 wasps per hectare!
  4. The highest number of nests recorded was 50 - 60 nests per hectare, the equivalent of 25 - 30 nests on a football field
  5. The largest nest ever found was four metres high and contained about four million cells
  6. There is a greater biomass of wasps (3.8kg/ha) in beech forest than all the native birds plus stoats and rodents put together
  7. The public voted wasps as “most disliked wildlife” (along with rats), because they spoil enjoyment of outdoor recreational activities
  8. Wasps destroy or seriously damage 8-9% of honeybee hives in New Zealand each year
  9. Wasps affect native foodwebs, and negatively affect the behaviour of native birds
  10. The predation rate of wasps on some native invertebrates is so high that the probability of their populations surviving through the wasp season is virtually nil


Landcare Research

Study evaluates costs of wasps to NZ

This report estimates that introduced wasps cost New Zealand’s economy more than $130 million dollars a year, with the biggest economic impacts on farming, beekeeping, horticulture and forestry workers. 
This assessment was based on a literature review. Information was collected from previous studies and from affected sectors in New Zealand to estimate the total costs of wasps, ie the costs that could be avoided and the opportunities that could be gained if wasps were not present in New Zealand.
New Zealand has some of the highest densities of German and common wasps in the world. Wasps have huge social and biological impacts; they are one of the most damaging invertebrate pests in New Zealand, harming our native birds and insects.
This study found that wasps also have a major financial impact on primary industries and the health sector. This includes:
  • more than $60 million a year in costs to pastoral farming from wasps disrupting bee pollination activities, reducing the amount of clover in pastures and increasing fertiliser costs.
  • almost $9 million a year cost to beekeepers from wasps attacking honey bees, robbing their honey and destroying hives.
  • wasp-related traffic accidents estimated to cost $1.4 million a year.
  • over $1 million each year spent on health costs from wasp stings.
  • on top of the direct costs, almost $60 million a year is lost in unrealised honey production from beech forest honeydew which is currently being monopolised by wasps. Honeydew is also a valuable energy source for kaka, tui and bellbirds.
Read More…

Not wasps but cicadas..


We see cicadas in large numbers here in New Zealand too! Been and gone here.

No: they don't sting!

Chain-sawing through a wasp nest

A swarm of wasps attacked a 60-year-old man recently after he accidentally chain-sawed through a wasp nest.


Costs of wasps to NZ

Pest wasps are costing New Zealand's economy $130 million a year, a new study says.
The impact of the introduced pests included wasp-related traffic incidents, costing $1.4 million a year, and more than $1 million in health costs from wasp stings.
But the greatest impact the study said was on the agricultural and horticultural sectors
See here for more information:


Mites to control wasps?

Landcare research is undertaking a study into the biological control of wasps with mites.

The cost to NZ primary industry of wasps is $130 million per annum according to Landcare Research


All about wasps in NZ

Introduced stinging wasps

The most offensive stingers are four introduced species of social wasp in the Vespidae family. These are pests in urban, rural and natural ecosystems. The worst two are of European origin, the black-and-yellow German and common wasps (Vespula germanica and Vespula vulgaris respectively), which attack and sting to defend their huge nests. Both species, especially the common wasp, have invaded native forest – kauri forests in the north and beech forests in the south.

Effects on native ecosystems

These wasps eat vast numbers of native insects, in direct competition with insect-eating birds. They also feed heavily on beech forest honeydew, an important food for native insects and birds such as kākā and bellbirds. Their numbers are highest in late summer, and in some South Island beech forests their combined weight may exceed that of all the birds. They can make outdoor recreation unpleasant and hazardous.